Because of this association he served five years in Stalinist prisons during the Communist regime and his family was deported to an isolated Hungarian village.

Greatly affected by the violence of the revolution and by the aberration of political systems in general, Istvan took refuge in drawing, and then, at the age of 12, in oil painting.

Gradually he achieved financial independence by accepting, along with the occasional sale of paintings, portrait commissions and few advertising illustrations.

For about fifteen years he painted a series of large-scale self-portraits, sometimes told to be aggressive and theatrical in character, which gave him an ambiguous reputation with the public.

Visceral and self-taught in work as in life, Sandorfi has since childhood distrusted 'things learned' and has remained true to his personal convictions.